metadata: sync with grpc

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

metadata/metadata.go

@@ -112,7 +112,7 @@ func (md Metadata) Get(k string) []string {
 		v, ok = md[strings.ToLower(k)]
 	}
 	if !ok {
-		v, ok = md[textproto.CanonicalMIMEHeaderKey(k)]
+		v = md[textproto.CanonicalMIMEHeaderKey(k)]
 	}
 	return v
 }
@@ -124,24 +124,13 @@ func (md Metadata) GetJoined(k string) string {
 }
 
 // Set sets the value of a given key with a slice of values.
-func (md Metadata) Add(key string, vals ...string) {
+func (md Metadata) Set(key string, vals ...string) {
 	if len(vals) == 0 {
 		return
 	}
 	md[key] = vals
 }
 
-// Set sets the value of a given key with a slice of values.
-func (md Metadata) Set(kvs ...string) {
-	if len(kvs)%2 == 1 {
-		panic(fmt.Sprintf("metadata: Set got an odd number of input pairs for metadata: %d", len(kvs)))
-	}
-
-	for i := 0; i < len(kvs); i += 2 {
-		md[kvs[i]] = append(md[kvs[i]], kvs[i+1])
-	}
-}
-
 // Append adds the values to key k, not overwriting what was already stored at
 // that key.
 func (md Metadata) Append(key string, vals ...string) {

metadata/metadata_test.go

@@ -5,6 +5,15 @@ import (
 	"testing"
 )
 
+func TesSet(t *testing.T) {
+	md := Pairs("key1", "val1", "key2", "val2")
+	md.Set("key1", "val2", "val3")
+	v := md.GetJoined("X-Request-Id")
+	if v != "val2, val3" {
+		t.Fatal("set not works")
+	}
+}
+
 /*
 func TestAppendOutgoingContextModify(t *testing.T) {
 	md := Pairs("key1", "val1")
@@ -47,18 +56,6 @@ func TestMultipleUsage(t *testing.T) {
 	_ = omd
 }
 
-func TestMetadataSetMultiple(t *testing.T) {
-	md := New(4)
-	md.Set("key1", "val1", "key2", "val2")
-
-	if v := md.GetJoined("key1"); v != "val1" {
-		t.Fatalf("invalid kv %#+v", md)
-	}
-	if v := md.GetJoined("key2"); v != "val2" {
-		t.Fatalf("invalid kv %#+v", md)
-	}
-}
-
 func TestPairs(t *testing.T) {
 	md := Pairs("key1", "val1", "key2", "val2")
 	if v := md.Get("key1"); v == nil {